Screw-making machine



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No. 512,156. Patented Jan. 2;, 1894.

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D. H. CHURCH. SCREW MAKING MACHINE.

Patented Jan 2, 1894..

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D. H. CHURCH. SCREW MAKING MACHINE.

(No Model.)

Patented Jan, 2

TATES DUANE H. CHURCH, OF 'WALTHAM, MASSACHUSETTS.

SCREW-MAKING MACHINE.

SPECIFICATION forming part of Letters Patent No. 512,156, dated January 2, 1894.

Application filed March 1,1892.

T aZZ whom it may concern Be it known that I, DUANE H. CHURCH, of WValtham, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Screw-Making Machines, of which the following is a specification. 1

This invention relates to machines for cutting screw -threads and particularly the threads of small screws such as are used in watches.

The invention has for its chief object to e11- able the operation of the thread cutting die to be automatically stopped when a predetermined length of thread has been formed on the wire or screw blank, and to this end it consists principally in a longitudinally movable die-carrying spindle normally held from rotating by friction while moving longitudinally, so that its screw cutting die will out a thread on a rotating blank onto which the die is moved by the forward longitudinal movement of the spindle, combined withmeans operated by the said forward movement of the spindle whereby the spindle may be released from friction at any predetermined point in its forward movement, and thus allowed to rotate loosely, so that the die will be rotated by the rotating blank and thus become inoperative.

Of the accompanying drawings forming a part of this specification, Figure 1 is a plan of a machine constructed according to my invention. Fig. 2 is an elevation partly in section of the same. Fig. 3 is an end elevation. Fig. 4 is a section on line 4 4 of Fig. 2. Figs. 5, 6 and 7 are details.

The frame of the machine consists of a bed 1, legs 2, 3 and base 4. I

Supported in the legs 2, 3, is a main-shaft 5 for carrying the operating cams of the machlne. Power is applied to the main-shaft in any convenient manner.

Mounted on the bed 1 to the left, is a standard 6 for supporting a spindle 7 having achuck 8 rotated in any suitable manner by pulley 9. This chuck spindle is of any suitable construction, and is operated by cam 10 acting on lever 11 having its fulcrum in the standard 6.

Mounted on the bed 1 to the right, is a transversely reciprocating slide 12, operated in one direction by a cam 13 acting on a lever 14 hav= Serial No. 423,414. (No model.)

ing itsfulcrum at 15 in the base 4; and in the opposite direction by spring 16 attached to slide 12 at 17 and to the frame of the machine at 18. Spring 16 and cam 13 act in opposition to each other to give the required reciprocating motion to the slide 12.

Mounted on slide 12 is an obliquely reciprocating slide 19 provided with a tool carrier 20. This slide 19 is for advancing and withdrawing the cutting off tool 21 of carrier 20.

Vertically disposed in slide 12 is a shaft 22 provided at its upper and lower ends respectively with levers 23 24. Cam on mainshaft 5 acts upon lever 24 and through shaft 22, lever 23 and slide 19, advances the toolto its work. WVhen released by cam 25 the slide 19 is retracted by spring 26 attached at 27 to the slide 19 and at 28 to the slide 12, until it comes in contact with stop screw 29 carried by slide 12.

Mounted upon slide 12 are standards 30 for supporting spindles 31, 32 provided with dies 33, 34. These spindles are of peculiar construction and one is a counterpart of the other. The function of die 33 is to cut the thread upon the prepared end 35 of wire 36, and die 34 finishes or perfects the same. The said dies 33 and 34 are of the construction ordinarily employed in cutting screw threads.

A description of one die spindle will answer for both. The forward end of spindle 31 turns in an ordinary bushing 37 and has free rotary and longitudinal motion. The rear end of the spindle is provided with a sleeve 38 formed with grooves 39, Figs. 2 and 6, to accommodate splines 40 carried by spindle 31. These splines 40 act to impart to sleeve 38 the rotary motion of spindle 31, but allow of a longitudinal movement of said spindle independent of the sleeve 38. The sleeve 38 turns in a two-part bushing 41 41 between which is placed a friction clutch 42, operated by a pin 43 carried by a lever 44 having its fulcrum at 45 in the standard 30. Suitably located beneath the bed 1, to be operated upon by cam 25, is a lever 47 carrying an adjustable finger 48 for acting upon vertical slide 49 which is brought by the motion of carriage 12 over finger 48 and is raised by said finger when it is desired to lift lever 44 to position shown in Fig. 2, said lever 44 having been previously released by catch 50.

Catch 50 is operated to trip lever 44 by a collar 51 carried by spindle 31 which acts to release lever 44 after the thread has been cut the desired length upon the end 35 of wire 36. The releasing of lever 44 lowers pin 43 andfriction clutch 42 releases sleeve 38. Spindle 31 is now free to turn and it partakes of the rotary motion of spindle 7.. Spindle 31 receives its longitudinal motion forward to advance die 33 to its work, through the lever 53 supported by a bracket 54 and operated by a cam 55 on main-shaft 5. Spindle 31 receives its backward motion for withdrawing die 33 from its work, through spring 56 confined between bushing 37 and the collar 51 carried by the spindle 31. The lever 53 is preferably made in two sections both mounted on the pivot 53', the upper section which bears on the spindle 31 being supported byaspring 80 attached to the lower section which bears on the cam 55. Said spring is sufficiently stifi to make the two sections act as one in moving the spindle forward, until the release or opening of the friction clutch. When this takes place the spring 80 permits the upper section of lever 53 to yield so that there is no forward movement of the spindle after it is permitted to rot-ate.

Mounted adjustably on slide 12 is a stop 57 against which the wire 36 is fed to determine the length of the piece to be cut off.

Mounted on main-shaft 5. is a earn 58 for acting on a lever 59 pivoted at 60 to the bed 4. After the thread hasbeen cut this lever 59 operates to shift the driving belt of the machine in orderto reverse the motion of spindle 7, to run the die 33 off, and allow spring 56 to act.

For accurately registering spindle 31 and its die 33 with spindle 7 which cuts the thread, it is preferable to provide a bell crank lever 70 fulcrumed at 71 to the frame of the machine, the lower arm being operated upon by the cam 55. The horizontal arm operates, by contact with a pin 72 carried by slide 12, to arrest the motion, of the slide 12 when die 33 is in proper relation for cutting the thread on the end 35.

The operation of the machine is as follows: The machine being set in motion, cam 10 through lever 11 operates to open chuck 8 and the wire 36 is fed to stop 57. Cam 10 then allows the chuck to close and the Wire is in position to be operated upon. Cam now acts 011 lever 24, and through shaft 22 and lever 23, moves the tool carrying slide 19 forward to bring tool 21 to operation, which cuts off the wire and turns the end down to the size it is desired for the thread to be cut. Cam 25 then releases lever 24 and allows spring 26 to return slide 19. These operations are taking place while the roller of arm 14 is riding on cam 13 from a to b, and as the path from a to b of the cam is concentric with shaft 5 the slide 12 is held stationary. The roller of lever 14 now travels from b to c on cam 13 and slide 12 is released, thus allowing spring 16 to act to bring spindle 31 in l ne with spindle 7, until pin 72 is in contact with bell-crank 70 which is adjusted to bring the 33 in proper relation for cutting the thread on the end 35. Cam 55 now acts on lever 53 and moves spindle 31 inward, the splines sliding in grooves 39 in the bushing 38. The spindle 31 moves forward until collar 51 moves catch sufficiently to disengage it. from lever 44. This point of disengagement determines the length of the thread to be out, for as lever 44 drops, the friction clutch is released, and spindle 31 instantly partakes of the rotary motion of spindle 7. Collar 51 is therefore set on spindle 31 according to length of thread it is desired to cut. Cam 5.5 now releases lever 53. Immediately following the disengagement of catch 50, cam 58 operates upon lever 59, which shifts the belting to reverse the rotation of spindle 7. Immediately following the action of cam 58 on lever 59, cam 25 acts upon lever 47, which operates the friction clutch 42 through con-' nections 43, 44, 48, 49 and 50, and spindle 31 is again firmly held against rotation; thus allowing the reverse action of spindle 7 to run the die 33 off the thread, and spring 56 returns spindle 31 to first position. (Jam 58 then releases lever 59. The belting is shifted back again and the forward rotation of spindle 7 is restored. Cam 25 new releases lever 47 and finger 48 falls below the line of the path of slide 12, and clutch 42 is held in action by catch 50. 0am now operates on bell crank and releases pin 72 to allow spring 16 to move the slide 12 when released by cam 13.

These operations take place whilethe roller of lever 14 is traveling from c to 01. Boiler of arm 14 now travels from d to e, and spring 16 acts upon slide 12 bringing spindle 32 in line with spindle 7. This spindle 32 is an exact counterpart of the spindle 31 both in construction and operation, except that 1ts die 34 is a finishing die and is for the purpose of finishing and polishing the thread formed by the die 33. Gain 55 now again acts upon lever 53, and the spindle 32 is moved forward as was spindle 31 until its collar 51 operates upon latch 50 and releases clutch 42. This forward movement runs the die 34 on the thread formed on the end 35 by die 33, and when the clutch 42' is released, cam 58 again acts upon lever 59, shifts the belting and reverses the spindle 7, as before. Immediately following this action of cam 58, cam 25 again acts and operates the clutch 42' in the same manner as clutch 42 was operated, thus holding spindle 32 from rotation and allowing thedie 34 to run oif the thread. Cam 55hav1ng previously released lever 53, spring 56 acts to return spindle 32 to first position. The operations upon spindle 32 take place while the roller of lever 14 is traveling from c to f; and the face of cam 13 from f to a returns slide 12 to first position, with stop 57 in place to gage the length of the piece to be cut offat the commencement of the operation.

The above described operations of the machine take place during one revolution of the main-shaft 5.

I claim '1. In a machine for cutting screw-threads, the combination of a rotating chuck for holding the work; a die-carrying spindle movable longitudinally toward and away from the said work-holding chuck, and also capable of rotary motion; a movable stop which prevents the die-carrying spindle from rotating while it is moving toward thework-holding chuck; and a trip which is actuated by theforward motion of the die-carrying spindle at a predetermined point and operates to disengage the stop from the spindle.

2. In a machine for cutting screw threads, the combination of a work holding and rotating chuck, a die carrying spindle movable longitudinally toward and from the chuck, a friction clutch adapted to prevent the rotation of the spindle while it is moving toward the work-holding chuck, and clutch opening devices operated by the longitudinal motion of the spindle whereby the clutch is made inoperative and the rotation of the spindle permitted at a predetermined point in the longitudinal movement of the spindle, toward the workholding chuck, as set forth.

3. In a machine for cutting screw threads, the combination of a work holding and rotatingchuck, a die carrying spindle movable longitudinally toward and from the chuck, a friction clutch adapted to prevent the rotation of the spindle without preventing its longitudinal movement, an adjustable collar or projection on said spindle, and clutch opening devices operated by said collar to make the clutch inoperative and permit the rotation of the spindle at a point in its forward movement determined by the adjustment of said collar or projection, as set forth.

4. In a machine for cutting screw threads, the combination of a work holding and rotat ing chuck, a longitudinally movable die carrying spindle, a sleeve or collar engaged with the spindle by means such as a spline and groove, whereby the spindle is permitted to move lengthwise independently and is prevented from rotating independently, said sleeve being normally free to rotate, a friction clutch adapted to lock said sleeve and thereby prevent the rotation of both the sleeve and spindle, and clutch opening devices operated by the longitudinal movement of the spindle, whereby the clutch is made inoperative and the rotation of the sleeve and spindle is permitted at a predetermined point in the forward movement of the latter, as set forth.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 31st day of October, A. D. 1891.

DUANE H. CHURCH.

Witnesses:

E. A. MARSH, A. D. HARRISON. 

